The phrase "in certain particulars" implies that something is true or accurate only in some specific aspects or details. There are various synonyms that can be used to convey similar meanings, such as "to some extent," "in some respects," "to a certain degree," "partially," "in particular situations," and "under specific circumstances." These phrases can be used interchangeably depending on the context and what the speaker or writer wants to emphasize. It is essential to choose the appropriate synonym to convey precisely what you mean so that your message is clear and easily understood by your audience.